Caribbean - Central America Weather

[Caribwxgirl]

Caribwxgirl, do you know if Jamaica has a radar? It would be very important to have that at this time.

Not certain. I will check.

[cycloneye]

8 PM Tropical Weather Outlook

SATELLITE IMAGES INDICATE THAT SHOWERS AND THUNDERSTORMS ASSOCIATED
WITH A TROPICAL WAVE OVER THE CENTRAL CARIBBEAN SEA HAVE CHANGED
LITTLE IN ORGANIZATION DURING THE PAST SEVERAL HOUR. HOWEVER...
SURFACE PRESSURES ARE LOW IN THE AREA...AND ENVIRONMENTAL
CONDITIONS ARE EXPECTED TO BECOME CONDUCIVE FOR A TROPICAL
DEPRESSION TO FORM DURING THE NEXT COUPLE OF DAYS. THIS SYSTEM HAS
A HIGH CHANCE...60 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING
THE NEXT 48 HOURS AS THE WAVE MOVES SLOWLY WESTWARD. HEAVY RAINS
FROM THIS DISTURBANCE OR POSSIBLE TROPICAL CYCLONE ARE LIKELY TO
SPREAD OVER JAMAICA...EASTERN CUBA...AND HISPANIOLA OVER THE NEXT
SEVERAL DAYS. THESE RAINS COULD PRODUCE LIFE-THREATENING FLASH
FLOODS AND MUD SLIDES...ESPECIALLY NEAR AREAS OF HIGH TERRAIN

[cycloneye]

Caribwxgirl, do you know if Jamaica has a radar? It would be very important to have that at this time.

Not certain. I will check.

Ok good.

[cycloneye]

8 PM Special Feature Discussion



TROPICAL WAVE IN THE CARIBBEAN SEA EXTENDS FROM 20N75W TO A 1007
MB LOW AT 15N73W TO 12N72W MOVING W AT 5-10 KT. LOW-LEVEL
CYCLONIC FLOW IS EVIDENT ON VISIBLE SATELLITE IMAGERY WITH TOTAL
PRECIPITABLE WATER IMAGERY ALSO INDICATING MAXIMUM VALUES OF
DEEP LAYER MOISTURE ACROSS THE CENTRAL CARIBBEAN BETWEEN
69W-77W. SCATTERED MODERATE CONVECTION IS N OF THE LOW CENTER
FROM 15N-18N BETWEEN 69W-74W TO INCLUDE PORTIONS OF HISPANIOLA.
AN UPPER LEVEL ANTICYCLONIC CENTERED IS OVER THIS TROPICAL WAVE.
ENVIRONMENTAL CONDITIONS ARE FORECAST TO BECOME MORE FAVORABLE
FOR DEVELOPMENT DURING THE NEXT DAY OR TWO AS THE DISTURBANCE
MOVES WESTWARD. THIS SYSTEM HAS A HIGH CHANCE OF BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS. HEAVY RAINS ARE
POSSIBLE WITH THIS SYSTEM OVER JAMAICA...EASTERN CUBA...AND
HISPANIOLA OVER THE NEXT SEVERAL DAYS. FLASH FLOODING AND MUD
SLIDES COULD OCCUR ESPECIALLY NEAR HIGH TERRAIN.

[tropicana]

Sat Oct 20-12 730pmET UPDATE

While the main cities of Kingston Norman Manley Intl and Montego Bay Sangster Intl Jamaica have not yet reported any significant rainfall today thus far at the airports, a complex of thunderstorms developed over SW portions of Jamaica and has been deluging this part of the island.... through 730pmET , 61mm of rain has fallen at Bluefields, Westmoreland on the SW coast of Jamaica!! This would be causing severe flooding for certain, we don't need the reports when they come in to know this. But this part of Jamaica has been unusually dry for the last month at least. Still, that's an inordinate amount of rain

-justin-

[Caribwxgirl]

I checked the one at the met service is temporarily down but I found this Jamaican weather site has one that seems to be working http://www.jaweather.com/radar-image.html

[Caribwxgirl]

Sat Oct 20-12 730pmET UPDATE

While the main cities of Kingston Norman Manley Intl and Montego Bay Sangster Intl Jamaica have not yet reported any significant rainfall today thus far at the airports, a complex of thunderstorms developed over SW portions of Jamaica and has been deluging this part of the island.... through 730pmET , 61mm of rain has fallen at Bluefields, Westmoreland on the SW coast of Jamaica!! This would be causing severe flooding for certain, we don't need the reports when they come in to know this. But this part of Jamaica has been unusually dry for the last month at least. Still, that's an inordinate amount of rain

-justin-

Hey there are you here in Jamaica right now?

[cycloneye]

I checked the one at the met service is temporarily down but I found this Jamaican weather site has one that seems to be working http://www.jaweather.com/radar-image.html

Good. At least there is a radar that will be important for the crucial next few days.Thanks for posting it.

[Gustywind]

Cycloneye, do you think that the Lesser Antilles could be impacted by 99L? What are the chances? Let's hope that nothing bad occurs from that (if any, should it verifies first!) . We will continue to monitor closely the situation is the best thing to do at this early stage.

[cycloneye]

Cycloneye, do you think that the Lesser Antilles could be impacted by 99L? What are the chances? Let's hope that nothing bad occurs from that (if any, should it verifies first!) . We will continue to monitor closely the situation is the best thing to do at this early stage.

The forecast by the models is that after it spends a few days in the Caribbean, it starts to track to the North or Northeast over Eastern Cuba or between Cuba and Haiti or over Hispanola. But is still early to say for sure what track it will take as it has not developed yet. That is why we in the whole Caribbean have to monitor the situation closely in the next couple of days.

[Gustywind]

Cycloneye, do you think that the Lesser Antilles could be impacted by 99L? What are the chances? Let's hope that nothing bad occurs from that (if any, should it verifies first!) . We will continue to monitor closely the situation is the best thing to do at this early stage.

The forecast by the models is that after it spends a few days in the Caribbean, it starts to track to the North or Northeast over Eastern Cuba or between Cuba and Haiti or over Hispanola. But is still early to say for sure what track it will take as it has not developed yet. That is why we in the whole Caribbean have to monitor the situation closely in the next couple of days.

Thanks to you , concerning the path looks like an enigma for the moment . We should keep an eye on it for sure. Guadeloupe will monitor it.

[cycloneye]

LATEST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SAN JUAN PR
846 PM AST SAT OCT 20 2012

.UPDATE...SOUNDING AT 21/00Z SHOWED A DRAMATIC DECREASE IN
MOISTURE OVER THE LAST 24 HOURS. AND IN THE SAME WAY SHOWER
ACTIVITY OVER THE COASTAL WATERS HAS ALSO DIMINISHED CONSIDERABLY
FROM LAST NIGHT. NEVERTHELESS...SHOWERS ARE STREAMING INTO EASTERN
PUERTO RICO AS FAR INLAND AS JUNCOS AND ALSO AROUND SAINT JOHN ON
THE WAY INTO SAINT THOMAS. LATEST WRF MODEL GUIDANCE AND HPC QPF
FORECAST ALSO SHOW GOOD POSSIBILITIES FOR RAIN ON EAST COAST OF
PUERTO RICO SO HAVE UPPED POPS FOR THAT AREA. OTHERWISE FORECAST
LOOKS ON TRACK WITH MODELS QUITE CONSISTENT FROM RUN TO RUN FOR
THE TIME BEING...AND ALL POINTING TO THE DEVELOPMENT OF THE LOW
PRESSURE ONCE IT REACHES THE WESTERN CARIBBEAN AND THEN RETURNING
TO THE ATLANTIC NORTH OF HISPANIOLA BY LATER NEXT WEEK.

&&

.AVIATION...
VFR CONDITIONS WILL PREVAIL ACROSS ALL TAF SITES THROUGH AT LEAST
21/17Z ALTHOUGH MOUNTAINS IN EASTERN PUERTO RICO ARE LIKELY TO BE
OBSCURED THROUGH 21/22Z. AFTERNOON CONVECTION COULD AFFECT TJMZ AND
TJBQ BTWN 21/17Z AND 21/21Z. AS A RESULT...MVFR/IFR CONDS AS WELL
AS MOUNTAIN OBSCURATIONS ARE POSSIBLE IN AND AROUND TJBQ AND TJMZ
SUNDAY AFTERNOON. 21/00Z TJSJ RAOB AS WELL AS LATEST TJUA VAD WIND
PROFILE SHOWED MAINLY SE WINDS AT 10 TO 15 KTS FM SFC TO 20 KFT.

[Caribwxgirl]

I checked the one at the met service is temporarily down but I found this Jamaican weather site has one that seems to be working http://www.jaweather.com/radar-image.html

Good. At least there is a radar that will be important for the crucial next few days.Thanks for posting it.

You're welcome

[cycloneye]

00z Surface Analysis.

[Macrocane]

The forecasts of heavy rains in El Salvador have verified and yesterday was the wettest day in the country since October 11 2011. This map shows the rainfall amounts in the country registered between 7 am yesterday and 7 am today:



The highest amounts were:

Chiltiupán 124.9 mm/4.92 inches (Highest 24 hours rainfall in El Salvador since October 11 2011)
Conchagua 122.2 mm/4.81 inches
Tepezontes 121.4 mm/4.78 inches
Huizucar 98.6 mm/3.88 inches
Citala 83.8 mm/3.30 inches

Minor flooding has been reported in the eastern part of the country, with dozens of people forced to evacuate their homes, fortunately no deaths have occurred.

[cycloneye]

Good morning. We continue to watch the progress of invest 99L in the next few days. Indirect effects may occur in PR.


AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
526 AM AST SUN OCT 21 2012

.SYNOPSIS...BROAD MID TO UPPER LEVEL HIGH PRESSURE RIDGE AND ASSOCIATED
ANTICYCLONIC WIND FLOW EXTENDS NORTHWARDS ACROSS THE REGION FROM THE
CENTRAL CARIBBEAN...WHILE TUTT LOW REMAINED ANCHORED ACROSS THE TROPICAL
ATLANTIC NORTHEAST OF THE LESSER ANTILLES. THE UPPER LEVEL WILL GRADUALLY
ERODE TODAY INTO EARLY NEXT WEEK... AS A LONG WAVE TROUGH EXITS THE
EASTERN SEABOARD OF THE UNITED STATES AND MOVES WESTWARD INTO THE WESTERN
ATLANTIC. THE UPPER TROUGH IS TO EVENTUALLY DEEPEN AND BECOME MORE AMPLIFIED
ACROSS THE NORTHWESTERN CARIBBEAN BY THE LATTER PART OF NEXT WEEK. AT
THE SURFACE AN ACTIVE TROPICAL WAVE AND AREA OF LOW PRESSURE NOW SOUTH
OF HAITI...AND SURFACE HIGH PRESSURE NORTH OF THE AREA WILL HELP MAINTAIN
LIGHT TO MODERATE EAST TO SOUTHEAST TRADE WINDS ACROSS THE REGION THROUGH
THE MIDDLE OF THE UPCOMING WEEK.

A TROPICAL WAVE AND ASSOCIATED CONVECTION WAS NOW BEING ENHANCED BY
THE PREVIOUSLY MENTIONED TUTT LOW WELL NORTHEAST OF THE LESSER ANTILLES.
MEANWHILE...A WEAKER TUTT INDUCED TROPICAL WAVE WAS QUICKLY APPROACHING
THE NORTHERN LEEWARDS THIS MORNING... WITH WAVE AXIS WAS NOW NEAR 60
WEST. NO SIGNIFICANT AMOUNTS OF CONVECTION IS ASSOCIATED WITH THIS
WAVE BUT SOME ISOLATED SHOWERS AND THUNDERSTORMS AND CLOUDINESS WAS
APPARENT ON LATEST SATELLITE IMAGERY ALONG WITH AN ASSOCIATED WEAK
LOW LEVEL VORTEX MOVING WESTWARD IN THE PREVAILING EASTERLY TRADES.

&&

.DISCUSSION...

SHORT TERM...ALTHOUGH LATEST SATELLITE IMAGERY AS WELL AS BLENDED
TWP ANALYSIS AND EARLIER 21/00Z UPPER AIR SOUNDINGS ACROSS THE REGION
SUGGESTED DECREASING PWAT VALUES AND SOMEWHAT DRIER AIR MASS ACROSS
THE REGION...STILL EXPECT LOCAL AND DIURNAL INFLUENCES ALONG WITH
AVAILABLE MOISTURE TO GIVE WAY TO ISOLATED TO SCATTERED CONVECTION
MAINLY ACROSS PARTS OF THE INTERIOR AND WEST SECTIONS OF PUERTO RICO
TODAY. LESSER CONVECTION IS EXPECTED OVER THE VIRGIN ISLANDS WHERE
ONLY FEW TO ISOLATED SHOWERS EXPECTED. LATER IN THE EVENING AND
TUESDAY MORNING EXPECTED WEAK EASTERLY PERTURBATION PREVIOUSLY MENTIONED
TO BRING SOME TRADE WIND SHOWERS TO THE COASTAL AREAS DURING THE
OVERNIGHT AND EARLY MORNING HOURS... FOLLOWED BY MAINLY LOCAL TERRAIN
AND DIURNALLY INDUCED AFTERNOON CONVECTION THROUGH WEDNESDAY.

LONG TERM...DURING THE LATTER PARTS OF THE WORK WEEK...INCREASING
LOW LEVEL SPEED CONVERGENCE COUPLED WITH GOOD VENTILATION BY UPPER
LEVEL ANTICYCLONIC FLOW FOLLOWED BY FAIR AMOUNTS OF DIVERGENCE ALOFT
LATER ON IN THE WEEK STILL LOOKS FAVORABLE FOR ACTIVE WEATHER AND
INCREASING CHANCES FOR URBAN AND FLASH FLOODING ACROSS THE REGION.
DEEP TROPICAL MOISTURE ADVECTION IS FORECAST BY THE LATEST GFS MODEL
GUIDANCE TO BE LIFTED UP ACROSS THE REGION...WHILE EUROPEAN MODEL NOW
SHOWED SLIGHTLY LESSER AMOUNTS BY THE END OF THE WEEK. HOWEVER BOTH
SUGGEST THE LOW PRESSURE SYSTEM IS EXPECTED TO DEVELOP INTO POSSIBLE
TROPICAL CYCLONE DURING THE NEXT FEW DAYS ACROSS OR JUST SOUTH OF
JAMAICA...THEN LIFT NORTHWARDS ACROSS EASTERN CUBA INTO THE SOUTHWEST
ATLANTIC BY THURSDAY OF NEXT WEEK. MORE TO COME ON THIS LATER AND
WILL CONTINUE TO MONITOR TO SEE HOW THIS UNFOLDS. REGARDLESS OF HOW
FAR WEST OR HOW MUCH THIS SYSTEM DEVELOPS...ALL MODELS SUGGEST THIS
SYSTEM WILL BE SIGNIFICANTLY LARGE AND BROAD ENOUGH TO DISRUPT THE
NORMAL LARGE SCALE SYNOPTIC PATTERN ACROSS THE CARIBBEAN BASIN
OVER THE NEXT SEVERAL DAYS. SO WILL BE MONITORING THIS FEATURE
VERY CLOSELY AS BOTH MARINE AND LOCAL WEATHER CONDITIONS ARE STILL
EXPECTED TO BE AFFECTED.

&&

.AVIATION...MOSTLY VFR CONDITIONS WILL PREVAIL ACROSS ALL TAF SITES
THROUGH AT LEAST 21/17Z ALTHOUGH MOUNTAINS IN EASTERN PUERTO RICO
ARE LIKELY TO BE OBSCURED THROUGH 21/22Z. AFTERNOON CONVECTION COULD
AFFECT TJMZ AND TJBQ BTWN 21/17Z AND 21/21Z. AS A RESULT...MVFR/IFR
CONDS AS WELL AS MOUNTAIN OBSCURATIONS ARE POSSIBLE IN AND AROUND
TJBQ AND TJMZ SUNDAY AFTERNOON. 21/00Z TJSJ RAOB AS WELL AS LATEST
TJUA VAD WIND PROFILE SHOWED MAINLY SE WINDS AT 10 TO 15 KTS FM SFC
TO 20 KFT.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU 88 77 88 78 / 30 30 30 20
STT 87 77 87 77 / 30 30 30 30

[Caribwxgirl]

From Jamaica's Met Service

October 21, 2012 at 5:00 a.m.

LOCAL WEATHER FORECAST

SIGNIFICANT FEATURE… A Tropical Wave with an associated area of Low Pressure is over the central Caribbean.

Comment
This system has the potential to develop into a Tropical Cyclone in
the next 24 to 48 hours, as it moves slowly towards the west.


24-HOUR FORECAST
This Morning… Partly cloudy with isolated thunderstorms.
This Afternoon… Expect widespread showers and thunderstorms across the island.
Tonight… Isolated showers and thunderstorms.


Maximum temperatures expected today for:
Kingston... 32 degrees Celsius
Montego Bay...32 degrees Celsius

3-DAY FORECAST (starting tomorrow)
Mon… Mostly cloudy with scattered showers and thunderstorms throughout the day.
Tue… Outbreaks of heavy thundershowers especially over eastern and central parishes.
Wed… Heavy thundershowers and possible storm force winds.

Regionally… A Trough is generating showers and thunderstorms over the western Caribbean.


ram

[cycloneye]

8 AM Tropical Weather Outlook up to 70%

SHOWERS AND THUNDERSTORMS HAVE BEEN INCREASING OVER THE PAST FEW
HOURS NEAR A TROPICAL WAVE AND BROAD AREA OF LOW PRESSURE OVER THE
CENTRAL CARIBBEAN SEA. ENVIRONMENTAL CONDITIONS APPEAR CONDUCIVE
FOR A TROPICAL DEPRESSION TO FORM DURING THE NEXT COUPLE OF DAYS...
AND THIS SYSTEM HAS A HIGH CHANCE...70 PERCENT...OF BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES SLOWLY
WESTWARD. HEAVY RAINS FROM THIS DISTURBANCE ARE LIKELY TO SPREAD
OVER JAMAICA...EASTERN CUBA...AND HISPANIOLA OVER THE NEXT SEVERAL
DAYS. THESE RAINS COULD PRODUCE LIFE-THREATENING FLASH FLOODS AND
MUD SLIDES...ESPECIALLY IN AREAS OF HIGH TERRAIN.

[cycloneye]

8 AM Special Feature discussion:

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 75W...FROM THE COAST OF
CUBA NEAR 20N TO THE COAST OF COLOMBIA. A 1006 MB LOW PRESSURE
CENTER IS ALONG THE WAVE NEAR 15N. CONVECTIVE PRECIPITATION...
SCATTERED MODERATE TO STRONG FROM 10N TO 18N BETWEEN 65W AND
74W...SCATTERED MODERATE TO ISOLATED STRONG FROM 12N TO 17N
BETWEEN 75W AND 81W. SURFACE PRESSURES ARE LOW IN THE AREA...AND
ENVIRONMENTAL CONDITIONS ARE EXPECTED TO BECOME CONDUCIVE FOR A
TROPICAL DEPRESSION TO FORM DURING THE NEXT FEW DAYS. THIS
SYSTEM HAS A HIGH CHANCE OF BECOMING A TROPICAL CYCLONE DURING
THE NEXT 48 HOURS AS THE WAVE MOVES SLOWLY WESTWARD. IT IS
LIKELY THAT HEAVY RAINS FROM THIS DISTURBANCE OR POSSIBLE
TROPICAL CYCLONE WILL SPREAD ACROSS JAMAICA...EASTERN CUBA...AND
HISPANIOLA DURING THE NEXT SEVERAL DAYS. IT IS POSSIBLE THAT
THESE RAINS MAY PRODUCE LIFE-THREATENING FLASH FLOODS AND MUD
SLIDES...ESPECIALLY NEAR AREAS OF HIGH TERRAIN.

[cycloneye]

Sundays discussion of 99L by Rob of Crownweather:

This post is NOT AN OFFICIAL FORECAST and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org. For Official Information please refer to the NHC and NWS products.

http://www.crownweather.com/?page_id=4557

Invest 99L Located In The Central Caribbean Likely To Become Tropical Storm & Possibly Hurricane Sandy This Week; Jamaica, Eastern Cuba, Hispaniola, The Bahamas & Possibly South Florida May Be Impacted By 99L/Sandy

Sunday, October 21, 2012 8:51 am
by Rob Lightbown

Invest 99L, which is an area of low pressure located over the central Caribbean is gradually becoming better organized this morning. Satellite loops this morning showed a definite increase in thunderstorm activity, especially on the eastern side of the low pressure system. Based on this and the fact that 99L is in a environment that is favorable for development, I think that this system will become a tropical depression by late tonight or Monday morning and then Tropical Storm Sandy by Monday evening or at the very latest Tuesday morning.

The various forecast guidance has shifted considerably further west in the forecast track of Sandy, especially once it gets north of Haiti and Cuba. It seems that the guidance is trending towards the Canadian model and this is potentially not so good news for the Bahamas, south Florida and potentially coastal sections of the southeastern US, Mid-Atlantic states and the northeastern US. Let’s take a quick look at each of the latest model guidance members:

The GFS model forecasts that Sandy to be to track over Jamaica on Wednesday, eastern Cuba on Thursday and then across the central and northwestern Bahamas on Friday coming quite close to southeastern Florida by Friday evening. From there, the GFS model forecasts that Sandy will phase with a strong trough of low pressure moving into New England on Sunday which if this verifies would bring very heavy rainfall and strong winds to much of New England on Sunday.

The European model forecasts that Sandy-to-be will track over Jamaica on Wednesday, eastern Cuba on Thursday and then across the central Bahamas on Friday and the northwestern Bahamas on Saturday. The European model does not phase Sandy with the eastward moving trough, but instead pulls it eastward out to near Bermuda by next Tuesday.

The Canadian model is the extreme of all of the model guidance in its phasing forecast. The Canadian model forecasts that Sandy will track just west of Jamaica on Thursday morning and then forecasts an extremely close brush if not landfall on southeastern Florida on Friday. The Canadian model also forecasts Sandy to phase with the eastward moving trough and become an extremely intense storm (central pressure of 962 millibars) near Virginia Beach by next Sunday morning.

It’s interesting to note that the UKMET model also hints at a track that is very similar to the Canadian model and shows it just west of Jamaica on Wednesday evening and then near the southern end of Andros Island in the Bahamas by Thursday evening.

So, here are my thoughts:
As I have really mentioned, I do think that 99L will be named Sandy by Tuesday at the very latest and a track north-northeastward right across Jamaica as a moderately strong tropical storm seems likely right now. The timeframe for this would be Wednesday evening. From there, Sandy may turn more northward and it “feels” the trough of low pressure to its west and starts to get captured by that trough. This means a track across the central/northwestern Bahamas is possible from near the southern end of Andros Island to right across Great Abaco Island on Thursday night or Friday morning. Now, a caveat here: A track further west very near southeastern Florida on Friday morning is certainly possible and this is something that will need to be watched for very closely.

Beyond that, I have concerns that the forecast guidance are trending towards the idea of Sandy phasing into the eastern trough of low pressure and potentially becoming an intense coastal storm for the Mid-Atlantic states and New England. At this point, it is a possibility and we have more than enough time to watch for this potential.

One final thought: Late season tropical storms and hurricanes in the Caribbean can be extremely fickle and difficult to forecast. If we take a look at climatology for Caribbean storms in late October, they tend to take a north-northwesterly track towards south Florida. Additionally, late season storms are notorious slow moving systems and do not escape out the Caribbean very quickly; so, it is plausible that the global models may be overdoing the track out of the Caribbean with this system. So, nothing is written in stone when it comes to 99L/Sandy and this is a system that bears very close scrutiny.

One thing that is for sure: 99L/Sandy is likely to bring heavy rainfall and life-threatening flash flooding and mudslides to Jamaica, eastern Cuba and Hispaniola for much of this week.